Percutaneous Osseointegrated Prosthetic Implant System

• US 20140156022A1
• Filed: 06/06/2012
• Published: 06/05/2014
• Est. Priority Date: 06/06/2011
• Status: Active Grant

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah Research Foundation (State of Utah)
• Inventors: Bachus, Kent N., Holt, Brian Mueller, Jeyapalina, Sujee, Beck, James Peter, Bloebaum, Roy
• Granted Patent: US 9,668,889 B2
• Time in Patent Office: Days
• US Class Current: 623/23.44
• CPC Class Codes: A61C 2008/0046 Textured surface, e.g. roughness, microstructure A61C8/0013 takes precedence
• CPC Class Codes: A61F 2/2814 Bone stump caps
• CPC Class Codes: A61F 2/78 Means for protecting prostheses or for attaching them to the body, e.g. bandages, harnesses, straps, or stockings for the limb stump
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/3694 with longitudinal bores
• CPC Class Codes: A61F 2002/7887 for connecting limb exoprostheses to the stump bone
• CPC Class Codes: F04C 2270/0421 Controlled or regulated

Abstract

An implant system for securing a prosthesis to a selected bone of a subject including a stem and an abutment. The stem includes a porous region that promotes osseointegration of the selected bone following implantation of the stem. The abutment is secured to the stem and is configured for secure attachment to the prosthesis. The stem and the abutment include ultra-low friction and/or highly polished surfaces at select locations that inhibit bio-adhesion.

Claims

1. An implant system for securing a prosthesis to a prepared site within a selected bone of a tissue region of a subject, the implant system comprising:

a stem having a longitudinal axis and a longitudinal length, the stem comprising;

an elongate shaft portion having an outer surface and defining an insertional end of the stem, the insertional end of the stem configured for receipt within the prepared site, the elongate shaft portion comprising a porous region having a selected length along the longitudinal axis of the stem; and

a collar portion defining a second end of the stem, the second end of the stem being spaced from the insertional end of the stem along the longitudinal axis of the stem, the collar portion defining a shoulder surface extending radially outwardly from the outer surface of the elongate shaft portion,

wherein the collar portion and the elongate shaft portion cooperate to define a central bore extending along at least a portion of the longitudinal length of the stem, and wherein the ratio between the longitudinal length of the stem and the selected length of the porous region ranges from about 3;

1 to about 10;

1; and

an abutment having a longitudinal axis, an attachment element, and a post having an outer surface and being operatively coupled to the attachment element, the attachment element of the abutment being configured for complementary receipt within the central bore of the stem such that the longitudinal axis of the abutment is substantially aligned with the longitudinal axis of the stem, at least a portion of the post being configured for selective secure attachment to the prosthesis,

wherein, upon secure receipt of the stem within the prepared site, the porous region of the stem is configured to promote integration of the selected bone of the subject into the stem and the shoulder surface is configured to abut the selected bone, and wherein at least a portion of the outer surface of the post of the abutment is configured to inhibit bio-adhesion.

2. The implant system of claim 1, wherein the porous region of the elongate shaft portion of the stem comprises porous titanium.

3. The implant system of claim 1, wherein the shoulder surface of the collar portion of the stem comprises a porous region configured to promote integration of the selected bone of the subject into the stem.

4. The implant system of claim 3, wherein the porous region of the shoulder surface of the collar portion of the stem comprises porous titanium.

5. The implant system of claim 1, wherein the collar portion of the stem comprises an outer surface, and wherein at least a portion of the outer surface of the collar portion is configured to inhibit bio-adhesion.

6. The implant system of claim 1, wherein the porous region of the elongate shaft portion of the stem is recessed relative to the outer surface of adjoining portions of the elongate shaft portion.

7. The implant system of claim 1, wherein the portion of the outer surface of the post of the abutment that is configured to inhibit bio-adhesion comprises an ultra-low friction surface.

8. The implant system of claim 1, wherein the portion of the outer surface of the post of the abutment that is configured to inhibit bio-adhesion comprises a highly polished surface.

9. The implant system of claim 1, wherein the post of the abutment has an insertional first end portion, an opposed second end portion, and a central portion positioned therebetween the first end portion and the second end portion along the longitudinal axis of the abutment, wherein the post is operatively coupled to the attachment element such that, upon complementary receipt of the attachment element within the implant stem, the insertional first end portion of the post is configured to be operatively positioned relative to the stem, and wherein the opposed second end portion of the post is configured for selective secure attachment to the prosthesis.

10. The implant system of claim 9, wherein the central portion of the post of the abutment is configured to inhibit bio-adhesion.

11. The implant system of claim 1, wherein the abutment further comprises a fixation element secured to the outer surface of the post at a selected position along the longitudinal axis of the abutment such that the fixation element extends radially outwardly relative to the outer surface of adjoining portions of the post, thereby defining a fixation surface configured to abut soft tissue of the subject proximate the prepared site.

12. An implant stem for securing an abutment in an operative position relative to a prepared site within a selected bone of a tissue region of a subject, the implant stem having a longitudinal axis and a longitudinal length, the implant stem comprising:

an elongate shaft portion defining an insertional end of the stem and having an outer surface defining an outer diameter of the elongate shaft portion, the insertional end of the stem configured for receipt within the prepared site, the elongate shaft portion comprising a porous region having a selected length along the longitudinal axis of the stem, the porous region of the elongate shaft portion being recessed relative to the outer surface of adjoining portions of the elongate shaft portion; and

a collar portion having an outer surface and defining a second end of the stem, the second end of the stem being spaced from the insertional end of the stem along the longitudinal axis of the stem, the collar portion defining a shoulder surface extending radially outwardly relative to the outer surface of adjoining portions of the elongate shaft portion, at least a portion of the outer surface of the collar portion being configured to inhibit bio-adhesion,

wherein the collar portion and the elongate shaft portion cooperate to define a central bore extending along at least a portion of the longitudinal length of the stem, the central bore being configured for secure receipt of a complementary portion of the abutment,

wherein the ratio between the longitudinal length of the stem and the selected length of the porous region ranges from about 3;

1 to about 10;

1, and

wherein the porous region of the elongate shaft portion is configured to promote integration of the selected bone of the subject into the stem.

19. The implant stem of claim 12, wherein the collar portion defines a second end of the stem, and wherein the collar portion defines an inner surface extending from the second end of the stem along at least a portion of the length of the stem, the inner surface of the collar portion being tapered inwardly along the longitudinal axis of the stem from the second end of the stem toward the insertional end of the stem.

13-18. -18. (canceled)

20-21. -21. (canceled)

22. An abutment having a longitudinal axis, the abutment configured for secure attachment to a prosthesis and an implant stem positioned within a prepared site of a selected bone of a tissue region of a subject, the abutment comprising:

an attachment element configured for secure attachment to the implant stem;

a post having an outer surface, an insertional first end portion, an opposed second end portion, and a central portion positioned therebetween the first end portion and the second end portion along the longitudinal axis of the abutment, the post being operatively coupled to the attachment element such that upon secure attachment of the attachment element to the implant stem, the insertional first end portion of the abutment is configured to be operatively positioned relative to the implant stem, and wherein the opposed second end of the abutment is configured for selective secure attachment to the prosthesis, at least a portion of the outer surface of the post being configured to inhibit bio-adhesion; and

a fixation element secured to the outer surface of the post at a selected position along the longitudinal axis of the abutment such that the fixation element extends radially outwardly relative to the outer surface of adjoining portions of the post, thereby defining a fixation surface configured to abut soft tissue of the subject proximate the prepared site.

24. The abutment of claim 22, wherein the post comprises a first metallic material and the fixation element comprises a second metallic material, and wherein the first metallic material is different from the second metallic material.

26. The abutment of claim 22, wherein the outer surface of the post comprises one or more tapered portions.

27. The abutment of claim 26, wherein the insertional first end portion of the post comprises a first tapered surface that is inwardly tapered along the longitudinal axis of the abutment moving away from the central portion of the post, and wherein the first tapered surface is configured for complementary receipt within the stem.

28. The abutment of claim 27, wherein the outer surface of the post defines a second tapered surface positioned proximate the interface between the insertional end portion and the central portion of the post, the second tapered surface being inwardly tapered along the longitudinal axis of the abutment moving away from the central portion of the post.

29. The abutment of claim 27, wherein the first and second tapered surfaces have respective orientation angles relative to the longitudinal axis of the abutment, and wherein the orientation angle of the second tapered surface is greater than the orientation angle of the first tapered surface by about 1 degree to about 1.5 degrees.

30. The abutment of claim 27, wherein the second tapered surface is configured to engage the fixation surface defined by the fixation element.

23. (canceled)

25. (canceled)

31-36. -36. (canceled)